Biodiversity, Invasive Species, Landowners, Prairie Pothole Region, Wildlife

Fighting invasive weeds with grass, grit and know-how 

Seeding forages in affected areas can provide a long-term, sustainable strategy for weed control

By Suzanne Joyce May 29, 2025

Kochia (foreground) is tolerant of heat, drought, and salt-affected soils. Seeding forages helps manage the weed in several ways, including remediating the salinity that kochia loves.

Many prairie farmers will tell you that, as far as weeds go, kochia is one tough nut to crack.

Traits of this invasive plant give it a competitive leg-up against agricultural crops; it tolerates heat, drought, and salt-affected soils and emerges earlier in spring than other plants. And seeds! At 10,000 to 25,000 seeds per plant, kochia is a prolific reproducer; thanks to its tumbleweed strategy, it’s also a master at dispersing those seeds, pretty much everywhere.

The sum total of these kochia characteristics is that it is a strong competitor for resources like light, nutrients, and water, and its presence often means reduced crop yields for the farmer.

While herbicides offered effective kochia control for a time, characteristics of the plant may enable it to adapt and outsmart herbicides faster than we can develop new ones. Within the span of less than a decade, resistance to glyphosate, an important herbicide for western Canadian farmers, ballooned. Today, all kochia is assumed to be glyphosate resistant, and resistance has been confirmed across several other herbicide groups, too.

Move over “Attack of the Killer Tomatoes”, there’s a new botanical horror flick in production and kochia is its star.

It’s a kochia jungle out there! Thanks to the competitive traits of this invasive weed and increasing herbicide resistance, kochia is becoming a real nuisance on the Prairies. © DUC

May the forage be with you

The same traits that make kochia so dastardly are also where its vulnerability lies. In particular, kochia’s short-lived seed bank makes it susceptible to management approaches that prevent seed set and limit the number of seeds returning to the soil.

That’s where perennial forages come in. Forages are mixtures of grasses and legumes that are seeded as hay or pasture and used as livestock feed. When forage crops are grown on kochia-affected areas, cutting time interferes with kochia’s critical period of flowering and seed production. Beyond that, certain forage plants have been shown to suppress the growth of kochia and reduce its emergence by up to 80 per cent.

If much of kochia’s advantage comes down to its tolerance of salt-affected soils, forages go one step further to counter it, remediating soil salinity and altering the conditions that kochia loves. Forage plants help keep naturally occurring salts deep within the soil profile, by keeping the ground covered and reducing evaporation, breaking up compaction and increasing moisture infiltration.

Through our Marginal Areas Program, DUC has been paying farmers a financial incentive to plant forages on marginal field areas that are prone to salinity and other challenges. Since MAP was launched in 2017 in Saskatchewan, the program has grown to over 16,000 acres signed with more than 300 producers.

With rising input costs and volatile market conditions, farmers need practical solutions to tackle weeds like kochia. Seeding forages in affected areas provides a long-term, sustainable strategy for weed control, a “one and done” approach that frees up resources for more productive field acres.

Adding acres of perennial forage to prairie landscapes helps manage invasive weeds while also boosting habitat for big game, ground-nesting birds and beneficial insects. © DUC

A true hero: Kochia management that helps the underdog, too

MAP provides an alternative solution to manage kochia—and it also supports prairie wildlife. Newly established areas of tame grassland are used by a variety of species, from big game to nesting waterfowl to tiny pollinators.

The story of mutual benefit doesn’t end there.

Growing a diverse crop rotation, including switching between spring- and winter-seeded, and annual and perennial crops, creates competition at varying points in the growing season that hits kochia hard. In addition to incentivizing tame grassland acres on the prairie landscape, DUC has been investing in research and development of winter-seeded crops since the 1990s. We continue to deliver a winter cereals program each fall, providing an important habitat-friendly crop option to prairie producers.

Fences, shelterbelts, aspen bluffs and other natural areas all create barriers that can prevent the tumble of tumbleweeds and kneecap kochia’s spread. DUC programs including conservation easements, purchases and leases that secure prairie habitats and support biodiversity also provide valuable physical barriers to tumbleweeds.

Programs and practices like these demonstrate that what makes sense for agriculture can benefit conservation, too. As the rate of land conversion and habitat loss across the Prairies accelerates, approaches that help manage invasive weeds and deliver other on-farm benefits while providing homes for wildlife are clear winners—for all prairie residents.

Including winter cereals in a crop rotation is a strategy to help manage kochia. Due largely to the different seeding time, these crops are also wildlife-friendly… this curlew sure thinks so! © DUC

Solutions for hardworking landscapes

DUC's conservation programs deliver on-farm benefits and safeguard prairie habitats while supporting biodiversity.

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